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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/notreached.h"
#include "base/time/time.h"
#include "ui/base/idle/idle.h"
#include "ui/base/idle/idle_internal.h"
#include "ui/display/screen.h"
#if defined(USE_DBUS)
#include "base/bind.h"
#include "base/logging.h"
#include "base/memory/scoped_refptr.h"
#include "base/no_destructor.h"
#include "base/task/task_runner.h"
#include "base/task/task_traits.h"
#include "base/task/thread_pool.h"
#include "dbus/bus.h"
#include "dbus/message.h"
#include "dbus/object_path.h"
#include "dbus/object_proxy.h"
#endif
namespace ui {
#if defined(USE_DBUS)
namespace {
const char kMethodName[] = "GetActive";
const char kSignalName[] = "ActiveChanged";
// Various names under which the service may be found in different Linux desktop
// environments.
struct {
const char* service_name;
const char* object_path;
const char* interface;
} constexpr kServices[] = {
// ksmserver, light-locker, etc.
{"org.freedesktop.ScreenSaver", "/org/freedesktop/ScreenSaver",
"org.freedesktop.ScreenSaver"},
// cinnamon-screensaver
{"org.cinnamon.ScreenSaver", "/org/cinnamon/ScreenSaver",
"org.cinnamon.ScreenSaver"},
// gnome-screensaver
{"org.gnome.ScreenSaver", "/org/gnome/ScreenSaver",
"org.gnome.ScreenSaver"},
// mate-screensaver
{"org.mate.ScreenSaver", "/org/mate/ScreenSaver", "org.mate.ScreenSaver"},
// xfce4-screensaver
{"org.xfce.ScreenSaver", "/org/xfce/ScreenSaver", "org.xfce.ScreenSaver"},
};
constexpr size_t kServiceCount = sizeof(kServices) / sizeof(kServices[0]);
// This class tries to find the name under which the ScreenSaver D-Bus service
// is registered, and if found the one, connects to the service and subscribes
// to its notifications.
class DBusScreenSaverWatcher {
public:
enum class LockState {
kUnknown,
kLocked,
kUnlocked,
};
DBusScreenSaverWatcher()
: task_runner_(
base::ThreadPool::CreateSequencedTaskRunner(base::TaskTraits(
base::MayBlock(),
base::TaskPriority::USER_VISIBLE,
base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN))) {
dbus::Bus::Options options;
options.bus_type = dbus::Bus::SESSION;
options.connection_type = dbus::Bus::PRIVATE;
options.dbus_task_runner = task_runner_;
bus_ = base::MakeRefCounted<dbus::Bus>(options);
TryCurrentService();
}
LockState lock_state() const { return lock_state_; }
private:
~DBusScreenSaverWatcher() = default;
// Starts the initialisation sequence for the current service. Failure at any
// step will increment the service counter and re-start the process.
void TryCurrentService() {
// Detach the proxy, if we have one from the previous attempt.
if (proxy_) {
task_runner_->PostTask(
FROM_HERE,
base::BindOnce(&dbus::ObjectProxy::Detach, base::Unretained(proxy_)));
proxy_ = nullptr;
}
if (current_service_ >= kServiceCount) {
if (current_service_ == kServiceCount) {
// Log the warning once.
LOG(WARNING)
<< "None of the known D-Bus ScreenSaver services could be used.";
++current_service_;
}
return;
}
// Calling methods on a non-existent service will lead to a timeout rather
// than an immediate error, so check for service existence first.
dbus::ObjectProxy* dbus_proxy = bus_->GetObjectProxy(
DBUS_SERVICE_DBUS, dbus::ObjectPath(DBUS_PATH_DBUS));
dbus::MethodCall name_has_owner_call(DBUS_INTERFACE_DBUS, "NameHasOwner");
dbus::MessageWriter writer(&name_has_owner_call);
writer.AppendString(kServices[current_service_].service_name);
dbus_proxy->CallMethod(
&name_has_owner_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
base::BindOnce(&DBusScreenSaverWatcher::OnServiceHasOwner,
weak_factory_.GetWeakPtr()));
}
void OnServiceHasOwner(dbus::Response* response) {
DCHECK_LT(current_service_, kServiceCount);
dbus::MessageReader reader(response);
bool owned = false;
if (!response || !reader.PopBool(&owned) || !owned) {
VLOG(1) << kServices[current_service_].service_name
<< " D-Bus service does not exist";
++current_service_;
return TryCurrentService();
}
// Now connect the ActiveChanged signal.
proxy_ = bus_->GetObjectProxy(
kServices[current_service_].service_name,
dbus::ObjectPath(kServices[current_service_].object_path));
proxy_->ConnectToSignal(
kServices[current_service_].interface, kSignalName,
base::BindRepeating(&DBusScreenSaverWatcher::OnActiveChanged,
weak_factory_.GetWeakPtr()),
base::BindOnce(&DBusScreenSaverWatcher::OnActiveChangedSignalConnected,
weak_factory_.GetWeakPtr()));
}
void OnActiveChangedSignalConnected(const std::string& interface,
const std::string& signal,
bool succeeded) {
DCHECK_LT(current_service_, kServiceCount);
DCHECK_EQ(interface, kServices[current_service_].interface);
DCHECK_EQ(signal, kSignalName);
if (!succeeded) {
VLOG(1) << "Cannot connect to " << kSignalName << " signal of "
<< interface << " D-Bus service";
++current_service_;
return TryCurrentService();
}
// Some service owners (e.g., gsd-screensaver-proxy) advertise the correct
// methods on org.freedesktop.ScreenSaver, but calling them will result in
// a NotImplemented DBus error. To ensure the service owner will send
// state change events, and to have the correct current state of the lock,
// make an explicit method call and check that no error is returned.
dbus::MethodCall method_call(kServices[current_service_].interface,
kMethodName);
proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
base::BindOnce(&DBusScreenSaverWatcher::OnGetActive,
weak_factory_.GetWeakPtr()));
}
void OnGetActive(dbus::Response* response) {
DCHECK_LT(current_service_, kServiceCount);
if (!response || !UpdateLockState(response)) {
VLOG(1)
<< "Call to " << kMethodName << " method of "
<< kServices[current_service_].interface << " D-Bus service failed";
++current_service_;
return TryCurrentService();
}
}
void OnActiveChanged(dbus::Signal* signal) { UpdateLockState(signal); }
bool UpdateLockState(dbus::Message* message) {
dbus::MessageReader reader(message);
bool active;
if (!reader.PopBool(&active) || reader.HasMoreData())
return false;
lock_state_ = active ? LockState::kLocked : LockState::kUnlocked;
return true;
}
LockState lock_state_ = LockState::kUnknown;
// Index of the service (in the kServices array) that is currently being
// initialised or used. A value out of bounds means that no working service
// was found.
size_t current_service_ = 0;
scoped_refptr<dbus::Bus> bus_;
scoped_refptr<base::SequencedTaskRunner> task_runner_;
dbus::ObjectProxy* proxy_ = nullptr;
base::WeakPtrFactory<DBusScreenSaverWatcher> weak_factory_{this};
};
DBusScreenSaverWatcher* GetDBusScreenSaverWatcher() {
static base::NoDestructor<DBusScreenSaverWatcher> impl;
return impl.get();
}
} // namespace
#endif // defined(USE_DBUS)
int CalculateIdleTime() {
auto* const screen = display::Screen::GetScreen();
// The screen can be nullptr in tests.
if (!screen)
return 0;
return screen->CalculateIdleTime().InSeconds();
}
bool CheckIdleStateIsLocked() {
if (IdleStateForTesting().has_value())
return IdleStateForTesting().value() == IDLE_STATE_LOCKED;
#if defined(USE_DBUS)
auto lock_state = GetDBusScreenSaverWatcher()->lock_state();
if (lock_state != DBusScreenSaverWatcher::LockState::kUnknown)
return lock_state == DBusScreenSaverWatcher::LockState::kLocked;
#endif
auto* const screen = display::Screen::GetScreen();
// The screen can be nullptr in tests.
if (!screen)
return false;
return screen->IsScreenSaverActive();
}
} // namespace ui
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